/*
 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

package javax.script;

/**
 * The optional interface implemented by ScriptEngines whose methods allow the invocation of
 * procedures in scripts that have previously been executed.
 *
 * @author Mike Grogan
 * @author A. Sundararajan
 * @since 1.6
 */
public interface Invocable {

  /**
   * Calls a method on a script object compiled during a previous script execution,
   * which is retained in the state of the <code>ScriptEngine</code>.
   *
   * @param name The name of the procedure to be called.
   * @param thiz If the procedure is a member  of a class defined in the script and thiz is an
   * instance of that class returned by a previous execution or invocation, the named method is
   * called through that instance.
   * @param args Arguments to pass to the procedure.  The rules for converting the arguments to
   * scripting variables are implementation-specific.
   * @return The value returned by the procedure.  The rules for converting the scripting variable
   * returned by the script method to a Java Object are implementation-specific.
   * @throws ScriptException if an error occurs during invocation of the method.
   * @throws NoSuchMethodException if method with given name or matching argument types cannot be
   * found.
   * @throws NullPointerException if the method name is null.
   * @throws IllegalArgumentException if the specified thiz is null or the specified Object is does
   * not represent a scripting object.
   */
  public Object invokeMethod(Object thiz, String name, Object... args)
      throws ScriptException, NoSuchMethodException;

  /**
   * Used to call top-level procedures and functions defined in scripts.
   *
   * @param name of the procedure or function to call
   * @param args Arguments to pass to the procedure or function
   * @return The value returned by the procedure or function
   * @throws ScriptException if an error occurs during invocation of the method.
   * @throws NoSuchMethodException if method with given name or matching argument types cannot be
   * found.
   * @throws NullPointerException if method name is null.
   */
  public Object invokeFunction(String name, Object... args)
      throws ScriptException, NoSuchMethodException;


  /**
   * Returns an implementation of an interface using functions compiled in
   * the interpreter. The methods of the interface
   * may be implemented using the <code>invokeFunction</code> method.
   *
   * @param <T> the type of the interface to return
   * @param clasz The <code>Class</code> object of the interface to return.
   * @return An instance of requested interface - null if the requested interface is unavailable, i.
   * e. if compiled functions in the <code>ScriptEngine</code> cannot be found matching the ones in
   * the requested interface.
   * @throws IllegalArgumentException if the specified <code>Class</code> object is null or is not
   * an interface.
   */
  public <T> T getInterface(Class<T> clasz);

  /**
   * Returns an implementation of an interface using member functions of
   * a scripting object compiled in the interpreter. The methods of the
   * interface may be implemented using the <code>invokeMethod</code> method.
   *
   * @param <T> the type of the interface to return
   * @param thiz The scripting object whose member functions are used to implement the methods of
   * the interface.
   * @param clasz The <code>Class</code> object of the interface to return.
   * @return An instance of requested interface - null if the requested interface is unavailable, i.
   * e. if compiled methods in the <code>ScriptEngine</code> cannot be found matching the ones in
   * the requested interface.
   * @throws IllegalArgumentException if the specified <code>Class</code> object is null or is not
   * an interface, or if the specified Object is null or does not represent a scripting object.
   */
  public <T> T getInterface(Object thiz, Class<T> clasz);

}
